The present invention relates to plastic containers including a substantially rigid wall portion, particularly plastic containers that use vacuum, as in an internal coating operation or that are hot fillable to facilitate resistance to deformation and improve the aesthetic display of a label.
Hot-fill containers are known in the art. When liquid contents that fill a container at elevated temperatures are permitted to cool, a strong internal pressure or vacuum is generated. Conventional hot-fill containers generally accommodate the vacuum pressure, which can be significant, by employing a rigid base portion (which may further include strengthening ribs or other formations) and flex panels that are configured in the sidewall portion of the container to accommodate the change in internal pressure.
A problem that sometimes occurs in connection with the use of flex panels in the sidewall of the container concerns labeling. Indentations, voids or spaces can sometimes be intentionally or unintentionally formed at or about the label mounting portion of the container. Such structural features can cause the label to wrinkle, tear, or otherwise distort and, among other things, can inhibit or prevent the prominent display of an aesthetically pleasing label. Moreover, some consumers may desire a container that is filled with product wherein a label is wrapped tightly around the container and is adhered to what feels like a solid and more rigid container sidewall.
Further, conventional hot fillable containers are commonly produced at a first location by a manufacturer and are then shipped or transported to a second location (often at the customer's facility) where they are filled with product contents and then labeled. In the case of hot-filled product containers, as the product contents cool, a vacuum pressure is created. Typically, the vacuum is accommodated at the second (“filling”) location by formations in the portions of the side wall of the container that are permitted to collapse or flex inwardly. In many instances employing conventional sidewall configurations, the internal vacuum can cause significant labeling problems, including those previously mentioned.
In addition, a coating procedure to coat the internal surface of a plastic container may use a vacuum in the container, as for example, a carbon coating. This may cause similar problems as those outlined above. Also, if one tries to light weight the container, the container would be prone to collapse.
It is, therefore, an object of the present invention to provide an improved plastic container with a strengthened body or sidewall structure.
It is a further object of the present invention to provide an improved container as aforesaid with a body or sidewall structure that resists deformation when a vacuum is formed within the container.
Further objects and advantages of the present invention will appear hereinbelow.